This 'RollerCoaster Tycoon' Maze Takes Trillions of Years to Complete

The maze will take simulated park guests park 6.6 * 10 ^ 19,758 years to complete. That is a very long time.
August 6, 2020, 2:05pm

Someone just created a maze in RollerCoaster Tycoon 2 that takes park guests 6.6 * 10 ^ 19,758 years to complete. 

“I tried coming up with something to put this number in perspective, but I just can’t,” said Marcel Vos, the maze’s creator, in a YouTube video sharing the maze

RollerCoaster Tycoon 2, a theme park management simulation, first came out in 2002. Players are tasked with creating and managing an amusement park by designing roller coasters, water rides, shops, and other attractions that are then enjoyed by computer-simulated park guests and visitors.

Although the game is nearly 20 years old, it has remained popular in part because of OpenRCT2, an open source re-implementation of the game that allows players much greater freedom in what they are able to build. Fans have created some incredibly intricate and complicated projects, including a roller coaster that theoretically takes 210 real-life days and 3,000 years of in-game time to complete.

Vos has built an online following in large part due to his Roller Coaster Tycoon 2 projects, and in the past has created a working calculator out of roller coasters that can add or multiply single digit numbers. In his latest project, published to YouTube last week, Vos has created an impossibly difficult maze that would theoretically take simulated park guests 6.6 *10 ^ 19,758 years to complete. To get a sense of just how long 6.6 *10 ^ 19,758 years is, Vos said “if you were to write this number out in a text editor, it would be almost six entire pages of zeros.”

“I like to do extreme things, and huge rides are about as extreme as you can get in Roller Coaster Tycoon 2,” Vos told Motherboard in an email. “The maze took about 6 hours to build, which is relatively quick because I was able to use a script to build the maze for me.”

The difficulty of the maze is in part due to its size, which fills up the entire simulated park and consists of 64,516 tiles. The maze itself only consists of tiles with a straight path and a series of small indents on the left side that lead to nowhere, but because the indents are on the left side the maze becomes extremely difficult for simulated guests to complete.

As Vos describes in his YouTube video, the simulated park guests use a path finding algorithm to solve the maze. Because of the way the algorithm is programmed, when dealing with a straight path with an indent on the left, there is a 37.5 percent chance that the guest will end up going back towards the entrance. When the guest is turned around, the indent will now be on the right, where there is only a 12.5 percent chance the guest will end up going back towards the exit. 

“This is why this maze is so impossible. When the guests are going in the correct direction there is a 37.5 percent chance that they will turn back. But when they are going in the wrong direction, the chance to turn back is three times as low,” Vos said in the video. “This creates a very heavy bias for walking back towards the entrance.”

Developers of OpenRCT2 appear to have caught wind of Vos’s video, and in what appears to be a friendly troll changed the maze pathfinding algorithm to no longer prefer a direction, meaning there is no longer a difference in the difficulty between left or right indented mazes. 

“I love that they've changed. It's an improvement to the game and that's what OpenRCT2 is for,” Vos said. “It also gave me another video to make which is also doing well on Youtube.”